A teenager who allegedly boarded a Jetstar flight armed with a shotgun has triggered a review of security at airports around Australia.

The 17-year-old is facing eight charges while a sheepshearer who stepped in to disarm him is being praised as a hero and has been offered free flights for life.

Questions are raised over how a 17-year-old boy was allegedly able to evade security at Avalon Airport and board a flight with a loaded shotgun.

Home Affairs Minister Tony Burke has initiated the audit to determine what security upgrades are necessary to prevent such incidents after a teenage alleged gunman tried to board a Jetstar flight.

A lack of police presence at the airport meant officers had to race nine kilometres to arrest a teenager who claimed to be carrying a bomb on board a Jetstar flight.

A teenager accused of attempting to hijack a Jetstar flight allegedly declared “I’ve got bombs in my bag” before he was tackled by passengers.

When the security crisis unfolded on Thursday afternoon, local police from Lara - nine kilometres away - were the ones that responded.

Several heroic passengers were able to detain a 17-year-old boy who allegedly dressed as a maintenance worker to board a Jetstar flight at an Australian airport with a shotgun and ammunition,

Home Affairs Minister Tony Burke has directed large regional airports to conduct an urgent risk assessment following a teenager allegedly attempting to board a Jetstar flight with a gun at Avalon airport.

A man is in custody after attempting to take a firearm on to a commercial flight that was due to depart Avalon Airport for Sydney on Thursday afternoon.